1. Field of the Invention
The present invention relates to a discharge apparatus for causing a discharge device to discharge, a method of controlling the discharge apparatus, and an imaging apparatus that includes the discharge apparatus as a flash apparatus for illuminating an object.
2. Description of the Related Art
In imaging apparatuses such as digital still cameras, a flash apparatus used as an auxiliary light source for photographing in the dark includes, for example, a discharge tube filled with xenon gas, a capacitor for storing charge for causing the discharge tube to discharge, and a discharge control device that controls electrical connection and disconnection between the capacitor and the discharge tube. The discharge tube is caused to discharge to generate a flash of light for external illumination.
In such a flash apparatus, when the discharge tube enters a discharging state, its impedance rapidly decreases, causing a large momentary discharge current to flow in the circuit. The large current may damage the discharge control device that controls electrical connection and disconnection between the capacitor and the charge tube. In addition, when the ambient temperature of the discharge tube increases, the discharge tube will more easily discharge. Hence, compared with the case of normal temperature, even a larger discharge current will flow in the circuit during discharging, and may damage the discharge control device that controls electrical connection and disconnection between the capacitor and the charge tube.
Japanese Unexamined Patent Application Publication No. 2005-310571 discloses a portable electronic apparatus having a camera function, where in order to prevent the ambient temperature of a lighting device from abnormally increasing, the portable electronic apparatus has a thermistor that senses the ambient temperature of the lighting device. When the portable electronic apparatus detects an abnormal condition, it stops supply of power to the lighting device.